通过经纬度获取地址信息之百度地图API

环境：Visual Studio 2013  C++

语言：C++

百度地图API

百度地图API接口：

1. 申请密钥
2. 填写信息
3. 创建应用（IP白名单记得填0.0.0.0/0）
4. 查看应用
5. 复制访问应用（AK）

坐标转换API接口文档：

1. 知道自己的AK (E4805d16520de693a3fe707cdc962045)
   
2. 知道对应转换的地址链接并了解格式中的含义

/************************************************************************/
/*                            网页操作		                            */
/************************************************************************/

// query locale place name
char* Gps_xjkg::QueryLocale(void)
{
	char PlaceName[256] = {};

	memcpy(PlaceName, CreateURL(),sizeof(PlaceName));
	AccessURL(PlaceName);

	GetURLStruct();
	
	CString placename(this->PlaceName);
	if (smps[KEY_PLACENAME_INFO])
		printf("本地地名：%s\n", placename);

	return PlaceName;
}


/*==========================================================
* Function   : CreateURL
* Description: 根据经纬度创建http请求链接
* Input      : 
* Return     : const char* URL		链接http地址
==========================================================*/
char* Gps_xjkg::CreateURL(void)
{
	char ctemp[256] = {};

	// add Baidu Base URL
	strcat_s(ctemp, Baidu_GPS);

	// add Baidu secret key
	strcat_s(ctemp, "/?ak=");
	strcat_s(ctemp, ak);

	// add longitude and latitude
	strcat_s(ctemp, "&location=");
	char tempaddr[32] = {};
	memcpy(tempaddr, dtoc(Rmc.GPS_Latitude), sizeof(tempaddr));
	strcat_s(ctemp, tempaddr);
	strcat_s(ctemp, ",");
	memcpy(tempaddr, dtoc(Rmc.GPS_Longitude), sizeof(tempaddr));
	strcat_s(ctemp, tempaddr);

	return ctemp;
}


/*==========================================================
* Function   : AccessURL
* Description: 链接百度地图API获取XML信息
* Input      : const string URL		链接http地址
* Return     : bool					失败返回false
==========================================================*/
#pragma comment(lib, "wininet.lib")
bool Gps_xjkg::AccessURL(const std::string URL)
{

	URL_COMPONENTS crackedURL;
	char szBuffer[1024] = {};// 缓冲区
	TCHAR szHostName[128] = {};
	TCHAR szUrlPath[256] = {};
	ZeroMemory(&crackedURL, sizeof (URL_COMPONENTS));
	crackedURL.dwStructSize = sizeof (URL_COMPONENTS);
	crackedURL.lpszHostName = szHostName;
	crackedURL.dwHostNameLength = sizeof(szHostName);
	crackedURL.lpszUrlPath = szUrlPath;
	crackedURL.dwUrlPathLength = sizeof(szUrlPath);

	std::wstring wstrURL;
	StringToWstring(wstrURL, URL);

	InternetCrackUrl(wstrURL.c_str(), wstrURL.length(), 0, &crackedURL);
	FILE* file = NULL;
	fopen_s(&file, "XJKG_GPS.xml", "wb");

	HINTERNET hInt, hConn, hReq;
	//启用HTTP建立并创建URL请求
	hInt = InternetOpen(_T("Microsoft Internet Explorer"), INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
	hConn = InternetConnect(hInt, crackedURL.lpszHostName, crackedURL.nPort, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
	hReq = HttpOpenRequest(hConn, _T("GET"), crackedURL.lpszUrlPath, NULL, _T(""), NULL, 0, 0);

	char buff[64] = {};
	DWORD dwLen = 0;
	BOOL bResult = FALSE;
	DWORD nBytesGet = 0;
	BOOL bEnd = FALSE;
	DWORD dwRetCode = 0;
	DWORD dwSizeOfRq = sizeof(DWORD);
	dwSizeOfRq = sizeof(buff);
	if (HttpSendRequest(hReq, NULL, 0, NULL, 0)
		&& HttpQueryInfo(hReq, HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER, &dwRetCode, &dwSizeOfRq, NULL)
		&& dwRetCode < 400)
		bResult = TRUE;

	hReq = HttpOpenRequest(hConn, _T("GET"), crackedURL.lpszUrlPath, NULL, _T(""), NULL, 0, 0);
	if (HttpSendRequest(hReq, NULL, 0, NULL, 0)
		&& HttpQueryInfo(hReq, HTTP_QUERY_STATUS_CODE | HTTP_QUERY_CONTENT_ENCODING, &dwRetCode, &dwSizeOfRq, NULL)
		&& dwRetCode < 400)
		bResult = TRUE;
	
	while (TRUE)
	{
		if (bResult)
		{
			// Begin
			bResult = InternetReadFile(hReq, szBuffer, sizeof(szBuffer), &dwLen);
			if (bResult)
			{
				nBytesGet += dwLen;
				if (dwLen == 0)
				{
					bEnd = TRUE;
					break;
				}
//				szBuffer
				fwrite(szBuffer, 1, dwLen, file);
			}
		}
		else // end
			break;
	}
	fclose(file);
	return true;
}

/*==========================================================
* Function   : GetURLStruct
* Description: 获取地址,并将地址放入类变量 PlaceName 中
* Input      : 
* Return     : char *dest			失败返回false
==========================================================*/
bool Gps_xjkg::GetURLStruct(void)
{
 	FILE* pfile = NULL;
 	fopen_s(&pfile, "XJKG_GPS.xml", "r");
 	if (!pfile){
		if (smps[KEY_ERROR_INFO])
 			printf("error: open file happen error.\n");

 		return false;
 	}
	char cbuff[1024] = {};
 	int size = fread(cbuff, 1024, 1, pfile);


	std::string str_begin = "";
	std::string str_end = "";
	// 字段首位
	char *addr_begin = NULL;
	addr_begin = strstr(cbuff, str_begin.c_str());
	addr_begin += str_begin.length();
	// 字段末尾
	char *addr_end = strstr(cbuff, str_end.c_str());

	if (addr_end < addr_begin)
	{
		fclose(pfile);
		if (smps[KEY_ERROR_INFO])
			printf("error: GetURLStruct exception!\n");

		return false;
	}
	// 转换字段
	memset(this->PlaceName, '\0', sizeof(this->PlaceName));
	int pos = 0;
	while (addr_begin != addr_end)
	{
		if (*addr_begin > 0){
			this->PlaceName[pos++] = *addr_begin++;
			continue;
		}

		char temp[4] = {};
		for (int i = 0; i < 3; ++i, addr_begin++)
			temp[i] = *addr_begin;
		
		this->PlaceName[pos++] = Getplacename(temp);
	}
	fclose(pfile);
	return true;
}

注：以上函数只是给出了大概的思路。并不能直接复制粘贴使用

函数大概思路流程：

1. 动态创建可用的 URL 链接
2. 访问对应的 URL 链接并将返回的数据，尽数拷贝到 本地临时文件
3. 获取 本地临时文件 有效信息